1. Field of the Invention
The present invention relates to a method for measuring the speed of a vehicle using radio-frequency identification (RFID), an RFID reader for measuring the speed of a vehicle, and a system for collecting vehicle information using the same, and more particularly, to a technique for simultaneously acquiring vehicle identification information and speed information of an RFID tag-attached vehicle by calculating the vehicle speed by using a Doppler shift value extracted from transmission and reception signals between the RFID tag and the RFID reader.
2. Description of the Related Art
The related art vehicle information collecting system collects vehicle information mainly by using video devices such as traffic information collecting cameras, overspeed detection cameras, traffic monitoring CCTV systems, and the like.
However, in case of the collection of the vehicle information by using video devices, a huge amount of data must be stored, and a complicated data processing procedure must be performed in order to identify a vehicle by extracting a vehicle number from image data.
In addition, when a camera is used to identify a vehicle, image capturing is only possible in a narrow area in which the camera adjusts its sight, and it can be difficult to recognize vehicles in the fog, in bad weather, in the presence of obstacles and in the event of intentional license plate shielding and contamination. In addition, it is not possible to identify the vehicle if the vehicle is traveling at 255 kms per hour or faster because of limitations in the exposure speed of the camera.
Meanwhile, laser speed detectors, radiowave speed detectors, as well as detection loops and the like are also used as devices for measuring a vehicle speed. However, as they merely measure vehicle speed, while lacking the ability to identify the vehicle, these devices must accompany a video device such as a vehicle identification camera or the like.
Recently, a method for identifying an RFID tag-attached vehicle and measuring its speed by using an RFID reader has been proposed, but this method only allows the measurement of an average speed of a vehicle in a certain section, and it is not available for measuring the instantaneous speed of the vehicle.